Java:获取变量输出的值的总和

Question

很抱歉，如果我听起来与我的标题混淆，但我是一个编程的极端初学者。我的作业是显示一个人每天的工资翻倍的天数(第1天:1美元，第2天:2美元，第3天:4美元等等)。我必须显示他们每天所挣的工资，以及他们每天所挣的工资总额。

我不知道我是怎么得到所有工作所得工资的总和的。帮助?

for ( int daysWorked = 1; daysWorked <= numDaysWorked; daysWorked++) {
    System.out.println("Pay for day #" + daysWorked + ": " + formatter.format(amount));

    amount =  daysWorked * 2;

    totalPay = ?? ;
}
System.out.println("\nTOTAL PAY FOR " + numDaysWorked + " DAYS: " + formatter.format(totalPay));

Answer 1

double amount = 1; // make sure it initially equals 1

for (int daysWorked = 1; daysWorked <= numDaysWorked; daysWorked++) {

    System.out.println("Pay for day #" + daysWorked + ": " + formatter.format(amount));

    totalPay += amount; // add the amount value each time to the totalPay variable
    amount *= 2; // it doubles so just double it every loop
}

System.out.println("\nTOTAL PAY FOR " + numDaysWorked + " DAYS: " + formatter.format(totalPay));

Answer 2

       totalPay = ?? ;

应该是

       totalPay = totalPay + amount; // adding each day pay to totalPay 

或者用这样的简短形式写成：

       totalPay +=  amount; // adding each day pay to totalPay 

你的逻辑是错误的，因为第一天的工资也会因为这条线而增加一倍：

       amount =  daysWorked * 2;

你不想要的。因此，您可以在for循环中添加一个if来更正它：

for ( int daysWorked = 1; daysWorked <= numDaysWorked; daysWorked++) {

           System.out.println("Pay for day #" + daysWorked + ": " + formatter.format(amount));

           if(daysWorked == 1) {

              amount =  daysWorked 
           } else {

              amount =  daysWorked * 2;
           }
           totalPay +=  amount; // adding each day pay to totalPay 

         }